Very interesting thread- I can tell you how pigeons are taught where they live and this may or may not help.
When the birds are young you put a wire door on the loft, this turn the loft into an aviary almost, they are then able to see they surroundings.
Before I forget, from the minute the birds are weened whilst being fed an almost cue is used, now I don't know what they use around the country but in plymouth it is either "come on, come on, come on then" or a sports whistle. This allows them to be called in by pretty much anyone.
So now they have seen the outside the next stage